One imagination puzzle.
Cross
Can you cut and reassemble a square so that you create a red cross of the same volume?
(A cross is made of 5 identical squares)
Hint
The solution is quite elegant.
If you are a mathematical type calculate how high the cross will be and how you can create this height.
Answer
I hope the picture is quite illustrating.
Another solutions exist this seems most elegant to me though. If you have a different one you can easily check if it is correct yourself.